/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.runners.core.metrics;



import com.bff.gaia.unified.model.pipeline.v1.MetricsApi.MonitoringInfo;

import com.bff.gaia.unified.model.pipeline.v1.MetricsApi.MonitoringInfoSpec;

import com.bff.gaia.unified.model.pipeline.v1.MetricsApi.MonitoringInfoSpecs;



import java.util.Arrays;

import java.util.HashSet;

import java.util.Optional;

import java.util.Set;



import static com.bff.gaia.unified.model.pipeline.v1.MetricsApi.monitoringInfoSpec;



/** Class implements validation of MonitoringInfos against MonitoringInfoSpecs. */

public class SpecMonitoringInfoValidator {

  protected final MonitoringInfoSpec[] specs;



  public SpecMonitoringInfoValidator() {

    specs =

        Arrays.stream(MonitoringInfoSpecs.Enum.values())

            // Filtering default value for "unknown" Enums. Coming from proto implementation.

            .filter(x -> !x.name().equals("UNRECOGNIZED"))

            .map(x -> x.getValueDescriptor().getOptions().getExtension(monitoringInfoSpec))

            .toArray(size -> new MonitoringInfoSpec[size]);

  }



  /**

   * Validates provided {link MonitoringInfo} against relevant {link MonitoringInfoSpecs} if

   * present.

   *

   * @return error string if validation fails.

   */

  public Optional<String> validate(MonitoringInfo monitoringInfo) {

    MonitoringInfoSpec spec = null;



    for (MonitoringInfoSpec specIterator : specs) {

      if (monitoringInfo.getUrn().startsWith(specIterator.getUrn())) {

        spec = specIterator;

        break;

      }

    }



    // Skip checking unknown MonitoringInfos

    if (spec == null) {

      return Optional.empty();

    }



    if (!monitoringInfo.getType().equals(spec.getTypeUrn())) {

      return Optional.of(

          String.format(

              "Monitoring info with urn: %s should have type: %s, received %s",

              monitoringInfo.getUrn(), spec.getTypeUrn(), monitoringInfo.getType()));

    }



    // TODO(ajamato): Tighten this restriction to use set equality, to catch unused

    Set<String> requiredLabels = new HashSet<>(spec.getRequiredLabelsList());

    if (!monitoringInfo.getLabelsMap().keySet().containsAll(requiredLabels)) {

      return Optional.of(

          String.format(

              "MonitoringInfo with urn: %s should have labels: %s, actual: %s",

              monitoringInfo.getUrn(), requiredLabels, monitoringInfo.getLabelsMap()));

    }



    return Optional.empty();

  }

}